Newsgroups: sci.space.policy,sci.space.history
From: Henry Spencer <henry@zoo.toronto.edu>
Subject: Re: NERVA and Timberwind (was: Re: HST as justification for STS)
Date: Wed, 23 Apr 1997 18:04:34 GMT

In article <335DCC4E.933@PROFS.ISCL1.silon.simis.com>,
Niels Stchedroff  <N.Stcehdroff@PROFS.ISCL1.silon.simis.com> wrote:
>> Revive the old "Tory" reactors used in Project Pluto...
>
>The same Project Pluto where it was debated whether the warheads were
>even needed, since the exhaust was so radio-active?

No, there was nothing particularly radioactive about the exhaust from the
Pluto ramjet.  (Well, it would undoubtedly have had a bit of contamination,
but not a lot.)  The reason why folks wondered whether the thing needed a
warhead was the radiation emitted by the engine itself (a completely
unshielded half-gigawatt reactor) plus the shockwave generated by a fairly
large aircraft doing Mach 3 at treetop height.

>Where are you planning to launch from???

If you don't fire up the ramjets until you reach supersonic speed, the
radiation dose on the ground would probably be fairly small.


If you want radiation hazards, I saw a paper a while back on building an
SSTO with a solid-core antimatter engine.  The particles from the proton-
antiproton reaction would be absorbed in a series of tungsten casings,
which would heat liquid hydrogen to provide the exhaust.  The performance
numbers looked interesting, until you saw the numbers on the gamma-ray
flux at liftoff.  Wow.
--
Committees do harm merely by existing.             |       Henry Spencer
                           -- Freeman Dyson        |   henry@zoo.toronto.edu

Newsgroups: sci.space.history
From: Henry Spencer <henry@zoo.toronto.edu>
Subject: Project Pluto (was Re: fission in space?)
Date: Tue, 23 Dec 1997 17:38:33 GMT

In article <67mdjm$88s@news2.aero.org>,
Greg Fruth <jetson@mustang.aero.org> wrote:
>> ...Even the best systems will produce
>> radioactive junk and so the exhaust is going to be radioactive...
>
>An officemate of mine once mentioned something called "Project Pluto".  IIRC,
>this was a nuclear thermal propulsion cruise missile under development in the
>60's (50's?) which had 3 "payloads": a large warhead for the primary target,
>small bomblets for targets en route, and the radioactive plume spewing from
>the engine, which would poison everything in its wake...

Actually, the radiation concern with Pluto was not so much the exhaust
plume as the direct radiation from a totally unshielded half-gigawatt
reactor.  There was also some small :-) effect from the sonic boom of a
large aircraft doing Mach 3 at treetop height.

Pluto was indeed real.  It was a serious project in the late 1950s and
early 1960s, undertaken partly as a hedge against the possibility that
ballistic missiles would quickly become vulnerable to defences.  It got
as far as successful ground tests of prototype nuclear ramjets.

Much of Pluto's rationale was lost when effective ABM systems failed to
appear.  The concept always had problems with attack routing -- many of
the approach routes to the Soviet Union are over friendly or neutral
territory -- and with detectability -- it might be hard to catch, but it
would be awfully easy to track, since a *less* stealthy aircraft is
difficult to imagine.  The deathblow was the problem of how to safely test
an ultra-high-speed necessarily-unmanned aircraft with global range and a
tendency to kill everything under its flight path.  Sure, you can run the
tests over the Pacific, but what happens when one has a navigation
failure?  And for that matter, assuming everything works and your test is
a success, what do you *do* with the thing at the end of the test?  It's
intensely radioactive and has no landing gear...
--
If NT is the answer, you didn't                 |     Henry Spencer
understand the question.  -- Peter Blake        | henry@zoo.toronto.edu

Newsgroups: sci.space.history
From: Henry Spencer <henry@zoo.toronto.edu>
Subject: Re: Project Pluto (was Re: fission in space?)
Date: Wed, 24 Dec 1997 05:15:59 GMT

In article <67pbub$87k@news2.aero.org>,
Greg Fruth <jetson@mustang.aero.org> wrote:
>I also wonder how they planned to launch the thing for real.  The crew on
>the ship, sub or bomber from which you launch it might take exception to
>being fried to a crisp upon ignition...

There was no particular need to forward-base Pluto, given that it could go
anywhere on Earth within six hours (assuming a direct route) under its own
power.  It was too big for practical mobile launch anyway.

>If it were land based, you'd run into the same problem of roasting everything
>near the launch site and on the flight path leading out of your terrirory...

You can't launch a ramjet under its own power anyway; as with Navaho and
such, they assumed rocket boost to ramjet operating speed.  The reactor
wouldn't have been "hot" until the ramjet started.  As for the problem of
the flight path, I'm not sure -- I have a vague impression that they may
simply have assumed coastal launch sites.
--
If NT is the answer, you didn't                 |     Henry Spencer
understand the question.  -- Peter Blake        | henry@zoo.toronto.edu

Newsgroups: sci.space.history
From: henry@spsystems.net (Henry Spencer)
Subject: nuclear-powered bombers (was Re: Wierd Early Moon Lander)
Date: Sat, 25 Mar 2000 05:30:17 GMT

In article <38DC315A.684E63BF@bellsouth.net>, Tom  <t2jr@bellsouth.net> wrote:
>> Years ago, a plastic model kit of a nuclear-powered bomber was on the
>> market...
>
>It was a mach-3-on-the-deck nuclear bomber. They were really serious
>about it. What killed it though was that someone finally piped up and
>asked where it was going to be tested. It seems that at mach 3 spewing
>radioactive exhaust, it would lay a swath of destruction a couple miles
>wide.

The latest issue of Aerospace Projects Review has a very interesting
article on this, including a map of the planned test routes -- over the
Pacific, with launch from Eniwetok.

The thing would definitely have been dangerous to be around.  Apart from
radioactive exhaust -- the engine tended to shed bits of crud, and worse,
the crude was part beryllium oxide, so it was chemically poisonous as well
as radioactive -- there was the small matter of a ferocious sonic boom,
not to mention an unshielded half-gigawatt reactor.

Although these were issues, and there were a number of problems with
testing a dangerous ultra-fast experimental unmanned aircraft with global
range (cruising range at 30kft was 72400 miles [!], and at 1kft this
declined to a mere 9450 miles -- at Mach 3.9 and 3.2 respectively), the
real killer was elsewhere.  The whole project was started as a hedge
against the possibility that ballistic-missile interceptors would develop
quickly and make ICBMs obsolete.  When that failed to happen, there was no
justification for continuing an expensive and difficult development effort
for a backup concept... especially since, by then, the Kennedy/Johnson
administration was trying to rein in the military's enthusiasm for more
and more expensive and unnecessary new high-tech weapons.

(By the way, I think the nuclear-powered bomber that started this thread
wasn't the project being discussed.  If dim memory serves, that kit
depicted a generic futuristic aircraft vaguely reminiscent of the B-70.
It might have been based on a real design -- originally the B-70 was the
CPB, Chemically Powered Bomber, and it had an NPB counterpart which never
got very far -- but it definitely wasn't SLAM, aka Pluto, which among
other things was wingless... wings being quite unnecessary at that speed
in thick air.)
--
Computer disaster in February?  Oh, you |  Henry Spencer   henry@spsystems.net
must mean the release of Windows 2000.  |      (aka henry@zoo.toronto.edu)

Newsgroups: sci.space.history
From: henry@spsystems.net (Henry Spencer)
Subject: Re: nuclear-powered bombers (was Re: Wierd Early Moon Lander)
Date: Sun, 26 Mar 2000 20:19:46 GMT

In article <memo.20000326141057.44807A@sjbradshaw.compulink.co.uk>,
Simon Bradshaw <filter@sjbradshaw.cix.co.uk> wrote:
>> ...but it definitely wasn't SLAM, aka Pluto, which
>> among other things was wingless... wings being quite unnecessary at that
>> speed in thick air.)
>
>Hmmm... my copy of the article in the Apr/May 1990 _Air & Space_ on Pluto
>has a number of illustrations that clearly show SLAM/Pluto as having
>wings. ... Of course, these illos might be
>somewhat fanciful artist's impressions...

I saw that article too, but in retrospect I think those were probably
artist's impressions.  The APR piece includes drawings and artwork from
the time, all of which show the missile as wingless.

(It's possible that the A&S artwork was based on early design studies
rather than on the more specific concept that was later pursued as SLAM.)

>...but very few if any
>terrain-following or sea-skimming missiles rely entirely on body lift.

In general they don't cruise at Mach 3+.  Pluto/SLAM had the advantage of
immense engine power with near-zero fuel consumption rates.

(Interestingly, the APR article includes a graph showing net thrust vs.
Mach number, for various reactor operating temperatures.  All the curves
peak fairly sharply at Mach 3.0-3.5; nuclear ramjets of reasonable size
and temperature really *want* to cruise at about that speed.)
--
Computer disaster in February?  Oh, you |  Henry Spencer   henry@spsystems.net
must mean the release of Windows 2000.  |      (aka henry@zoo.toronto.edu)

From: Bill Higgins-- Beam Jockey <higgins@fnal.gov>
Newsgroups: sci.space.history
Subject: Re: nuclear-powered bombers (was Re: Wierd Early Moon Lander)
Date: Tue, 28 Mar 2000 11:28:35 -0600

On Sat, 25 Mar 2000, Henry Spencer wrote:

> The latest issue of Aerospace Projects Review has a very interesting
> article on this, including a map of the planned test routes -- over the
> Pacific, with launch from Eniwetok.

Is this Scott Lowther's publication?

Anyway, I wish to pipe up, as I usually do when this subject surfaces, to
recommend Brian Bikowicz's survey of the U.S. "Aircraft Nuclear Propulsion"
program of the 1950s.

See  <http://www.islandone.org/Propulsion/AtomPlane.html>.

--
    I'm one Apollo child who went into Engineering | Bill Higgins, Fermilab
                   and now I wish to hell my folks | Internet:
     had sent me to bed early on July 20, 1969 and | higgins@fnal.fnal.gov
forced me to go into either pre-law or accounting. |
        --Bill Von Elm (wvonelm1@vaxa.hofstra.edu) |

Newsgroups: sci.space.history
From: henry@spsystems.net (Henry Spencer)
Subject: Re: nuclear-powered bombers (was Re: Wierd Early Moon Lander)
Date: Tue, 28 Mar 2000 23:14:06 GMT

In article <Pine.SGI.4.05.10003281108530.25512-100000@fsgi02.fnal.gov>,
Bill Higgins-- Beam Jockey  <higgins@fnal.gov> wrote:
>> The latest issue of Aerospace Projects Review has a very interesting
>> article on this, including a map of the planned test routes -- over the
>> Pacific, with launch from Eniwetok.
>
>Is this Scott Lowther's publication?

Right.  http://www.webcreations.com/ptm/apr/apr.htm for more details.
--
Computer disaster in February?  Oh, you |  Henry Spencer   henry@spsystems.net
must mean the release of Windows 2000.  |      (aka henry@zoo.toronto.edu)